JPS58111846A - Polypropylene composition - Google Patents

Abstract

PURPOSE:To provide a compsn. with superior moldability, capable of giving moldings excellent in impact resistance, coatability, and appearance, consisting mainly of a crystalline ethylene/propylene block copolymer and containing an amorphous ethylene/propylene copolymer and talc. CONSTITUTION:The titled compsn. comprises 40-75wt% crystalline ethylene/ propylene block copolymer, ethylene content of 5-10wt%, boiling n-heptane insol. of PP moiety >=97%, intrinsic viscosity (decalin, 135 deg.C) of p-xylene sol. of PP moiety (ordinary temp.) of 2.5-4, and melt flow index of 11-70; 40-40wt% amorphous ethylene/propylene copolymer, intrinsic viscosity (decalin, 135 deg.C) of 1.0-2.0 and Mooney viscosity ML1+4 (100 deg.C) of 5-40; and 5-20wt% talc, average particle size of 0.1-5mu. The compsn. is superior in moldablity and capable of giving moldings excellent in impact resistance, coatability, and appearance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polypropylene composition, and more particularly, it provides a molded article containing a crystalline ethylene-propylene block copolymer as a main component, and which has particularly excellent impact resistance, paintability, and appearance. can.

Furthermore, the present invention relates to a polypropylene composition with excellent moldability.

Crystalline polypropylene is used in various molded products that require physical properties such as rigidity and resistance to heat deformation. Poor impact resistance and paintability, rigidity,
It has the disadvantage that it cannot be used in applications that require side heat deformability, impact resistance, and paintability at the same time.

In order to improve the impact resistance and paintability of crystalline polypropylene, we used a crystalline ethylene-propylene prosol copolymer as the crystalline polypropylene.

Furthermore, proposals have been made for polypropylene compositions in which an amorphous ethylene-propylene copolymer is blended with this, or methods in which a crystalline ethylene-propylene block copolymer is blended with a regular ethylene-propylene copolymer and various types of polyethylene. There is.

However, these conventionally proposed polypropylene compositions have the disadvantage that the above-mentioned properties such as rigidity and heat deformation resistance inherent to the crystalline ethylene-propylene Bronok copolymer are deteriorated.

Therefore, as an invention intended to improve the drawbacks of the polypropylene compositions proposed in the past,
No. 64257 describes an invention entitled ``1 Impact Resistant Resin Composition''. This publication discloses a resin composition with improved low-temperature impact properties, which is composed of a crystalline ethylene-propylene brochloride copolymer, an amorphous ethylene-α-olefin copolymer, and iodine talc. The publication also states that this composition has higher low-temperature impact strength than conventional crystalline ethylene-propylene zolonoc copolymer.

(It includes a statement that the paintability is greatly improved and examples are given.)

The compositions described in each example of the above publication are as follows.

Melt flow index is 715 as f remer component
A crystalline ethylene-propylene block copolymer, an ethylene-propylene-nonconjugated diene copolymer with a melt flow index of 0.4, or an amorphous ethylene-propylene copolymer with a melt flow index of 0.8. It is.

All of the above polymers have very high molecular weights. For this reason, the above composition is rigid.

Although the purpose of obtaining polypropylene molded products with excellent heat deformation resistance and impact strength has been sufficiently achieved,
The resulting molded product has disadvantages in that its appearance is poor due to the occurrence of flow marks on its surface, and its paintability is insufficient, resulting in a low commercial value of the molded product. Therefore, although the molded product obtained from the above composition can be used for some applications where the appearance can be ignored, the appearance is important as well as the mechanical properties, such as various parts for automobiles, especially bumpers. It is not suitable for the intended use.

Therefore, by molding the conventionally known crystalline ethylene-globylenebronoch copolymer, it was not possible to obtain a molded product with a good balance between rigidity and impact strength, paintability, and appearance. be.

Therefore, the inventors conducted extensive research with the aim of obtaining a polypropylene composition that has high Izotsu impact strength at low temperatures, has a good balance between rigidity and impact strength, and can provide molded products with excellent appearance and paintability. As a result, a specific crystalline ethylene-propylene block copolymer,
The above object was achieved by obtaining a composition containing an amorphous ethylene-propylene copolymer and talc in a specific ratio, and the present invention was completed.

That is, this invention has an ethylene content of 5 to 10% by weight, a polypropylene component insoluble in boiling n-heptane of 97% by weight or more, and a normal temperature para-xylene soluble fraction (decalin, 135°C) of 2.5 to 4.゜Crystalline ethylene-propylene block copolymer with melt flow index 11-70, weight 40-75, intrinsic viscosity (Decalin, 135
°C)l, 0-2.0. Mooney viscosity ML1+4 (1
00°C) 5 to 40 amorphous ethylene-propylene copolymer 20 to 40 weight coefficient, and an average particle size of 0.1 to 5 microns. The present invention relates to a polypropylene composition comprising r5 to 20% by weight.

The polypropylene composition of this invention has a flexural modulus of 9 s
o o o Kg/cd or more, Izot impact strength at -30°C is 5 Kg/c-v'on or more, and paint residual rate is 100% according to the substrate test for paintability described below.

No flow marks were observed, and the original rigidity and heat deformation resistance of the crystalline ethylene-glopylene bronoch copolymer were hardly impaired, and the impact resistance, paintability, and appearance at low temperatures were improved. Can be molded into improved molded articles. In particular, the polypropylene composition of the present invention does not generate flow marks even when molded into large molded products, for example, large molded products with a length of 1 m or more, and has a glossy and good appearance. , can be molded into high quality bumpers.

In addition, the polypropylene composition of the present invention has a melt flow index of 7 or more, and is a polypropylene composition in which a conventional easily crystallized ethylene-zolopylene brosox copolymer is blended with an i-type ethylene-propylene copolymer and talc. The molding processability is also the same, or even improved, compared to the conventional material.

The crystalline ethylene-propylene block copolymer used in the polypropylene composition of the present invention has an ethylene content of 5 to 10% by weight. is 97% by weight or more, and is soluble in para-xylene at room temperature (consisting of an amorphous ethylene-propylene copolymer and a low molecular weight polymer)
has an intrinsic viscosity (decalin, 135°C) of 2.5 to 4, and a melt flow index of 11 to 60. Preferably it is 12-50.

In this specification, the boiling n-hebutane insoluble portion of the polypropylene component refers to the crystalline polypropylene (sometimes referred to as matrix) used in the block copolymerization reaction.
Refers to the insoluble portion of boiling n-hebutane. When the above ethylene content is less than 5% by weight, the rigidity of the molded article decreases when the polypropylene composition is molded. In addition, the boiling n-hebutane insoluble content of the above polypropylene component is 97%.
If the commercial quantity is less than
/I, and is soluble in para-xylene at room temperature.
If the intrinsic viscosity (decalin, 135℃) is less than 2.5, the Izot impact strength at 30℃ of the molded product is 5.
Kp becomes smaller, and when it exceeds 4, the paintability of the molded product decreases. It was a cabinet. If the above melt flow index is less than 11, the appearance of the molded product, especially the appearance of large molded products, and the molding processability of the polypropylene composition, especially into large molded products, will deteriorate; impact resistance decreases. In either case, the polypropylene composition cannot be used as a material for molded articles that require not only rigidity, heat deformation resistance, low-temperature impact resistance, and paintability, but also excellent appearance.

1. The amount of crystalline ethylene and ropylenezolonoc copolymer in the composition is 40 to 75% by weight, preferably 45 to 70% by weight.
Contains 50%. If the above content is less than 40% by weight, the flexural modulus of the molded product is 8000 Kg/cd.
If the weight exceeds 75%, the impact resistance of the molded product at low temperatures will decrease.

Crystalline ethylene-propylene block copolymer c.

Two or more types may be used as long as the total amount is within the above range.

The amorphous ethylene-propylene copolymer used in the polypropylene composition of this invention is.

The intrinsic viscosity (decalin, 135°C) is 1.0 to 2.0, and the Mooney viscosity MLl+4 (l OO°C) is 5
~40. Preferably it is 10-40.

If the above-mentioned intrinsic viscosity and Mooney viscosity are smaller than the above-mentioned lower limit, the impact resistance of the molded article at low temperature will decrease, and if the intrinsic viscosity and Mooney viscosity are larger than the above-mentioned upper limit, the amorphous ethylene-propylene copolymer Compatibility with the crystalline ethylene-propylene fluoromonocopolymer used, which has a large melt flow index, becomes poor;
The outside of the molded product deteriorates.

The amorphous ethylene-propylene copolymer is present in the composition in an amount of 20 to 40% by weight, preferably 20 to 350 to 35% by weight.
If the above content is less than 20% by weight, the impact resistance and paintability at low temperatures of the molded product will decrease, and if it exceeds 40% by weight, the flexural modulus of the molded product will be 8000 h/c.
d becomes smaller.

The talc used in the polypropylene composition of this invention has an average particle size of 0.1 to 5 microns.

Preferably it is 0.5 to 3 microns. If the above average particle size is less than 0.1 micron, it becomes difficult to uniformly disperse talc in the composition, and if it exceeds 5 micron, the paintability and appearance of the molded article will deteriorate.

The talc is contained in the composition in an amount of 5 to 20% by weight. If the talc content is less than 5% by weight, the rigidity of the molded product will not be improved, and if it exceeds 20% by weight, the impact resistance of the molded product at low temperatures will decrease.

Yukuri may be used untreated, but in order to improve adhesion or dispersibility with Matrix 1, various organic titanate coupling agents, silane coupling agents,
Particles whose surfaces are coated with fatty acids, fatty acid metal salts, fatty acid esters, fatty acid amides, etc. may also be used.

The polypropylene composition of the present invention can be prepared by heating each component using a Banbury mixer (9), a kneader, a FOM, a twin-screw extruder, a single-screw extruder, and other mixing machines, particularly preferably a Banbury mixer. It can be easily obtained by kneading with

In order to further improve the various performances of molded articles molded from the polypropylene composition of the present invention, 2,6-di-tert-butylphenol, 2, 6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-α-dimethylamino-para-cresol, 6-(4- Hydroxy-3,5-
Di-tert-butyl colored nilino-2,4-bisoctyl-thio-1,3°5-triazine9. p-octadecyl-3-
(,4'-hydroxy-3t5'-di-tert-butylphenyl)gropione), 2,6-di-tert-butyl-4-
Methylphenol (BHT), )lis-(2-methyl-
4-Hydroxy-5-tert-butylphenyl)butane.

Tetrakis-[methylene 3-(3z5'-di-tert-butyl-4'-hydroxyphenyl)propionate comethane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4 Antioxidants such as -hydroxybenzyl)benzene and dilaurylthiodipropionate: 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 4-dobutyloxy-2-hydroxybenzophenone, Nickel-bis-(〇-ethyl-3,5-ditert-butyl-4-hydroxybenzyl)phosphonate,
2-hydroxy-4-n-octoxybenzophenone,
2-(2'-Hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenztriazole, 2-
(2-Hydroxy-3-5'-di-tert-butyl-7enyl)-5-chlorobenztriazole, bis-(2,6-
dimethyl-4-piperidyl) sebacate.

UV absorbers such as bis-(2,2,6,6-tetramethyl-4-piperidyl) sebacate: antimony trioxide, )! Flame retardants such as carbon plaque, titanium oxide, etc. Polymers that improve the rigidity of molded products such as high-density polyethylene Paintability improvers such as magnesium dibenzoate (in amounts up to 10% by weight relative to the composition):
A coating agent such as a process oil, a lubricant such as a fatty acid metal salt, an antistatic agent such as a binder and oxyethylene alkyl ether, etc. can also be blended.

The polypropylene compositions of the invention are molded by methods known per se 9, for example by injection molding.

To obtain a molded product that has a good balance between rigidity and impact strength, has excellent paintability and appearance, and has a good appearance even when molded into a large molded product, in particular, without the occurrence of 70-marks. I can do it.

Examples and comparative examples are shown below. In the following description, [parts to J and r%J are each "parts by weight".

Means “wt%” and melt flow index is AS
TM D1238 to 1 surface cloth is ASTM D5
23, the tensile yield point strength is A, STMD638 is 1, and the flexural modulus is AST'M D790.

Izod impact strength was measured according to ASTM D256.

Example 1 Ethylene content 8.0%, boiling n of polypropylene component
- Hebutane insoluble content of 97% or more, room temperature) - Intrinsic viscosity of xylene soluble content (decalin, 135"C) 2.5 to 4.
0. Crystalline ethylene with a melt flow index of 30
20 parts of propylene block copolymer (hereinafter referred to as EP copolymer A), ethylene content 9.0%, boiling n-heptane insoluble content of polypropylene component 97% or more, normal temperature para-xylene soluble content (intrinsic viscosity (decalin) , 135℃)
2.5-4. O.

43 parts of a crystalline ethylene-propylene block copolymer (hereinafter referred to as EP copolymer B) with a melt flow index of 15, an intrinsic viscosity (decalin, 135°C) of 1.5.
Mooney viscosity ML□+, (100°C) 27 parts of amorphous ethylene-propylene copolymer (hereinafter referred to as EPR-A), 10 parts of slag with an average particle size of 2μ, BHTo,
05 parts, tetrakis-[methylene 3 = (3', 5
'-Ditert-butyl-4'-hydroxyphenyl)propionate cometaf 0.3 part,
0.3 part of 0-ethyl-zt5-symtributyl-4-hydroxybenzyl)phosphonate was mixed with a Banbury mixer at 180°C for 12 minutes and then granulated.

0.6 parts of carbon black was added to 100 parts of the obtained belene, and the mixture was kneaded in a single-screw extruder with a cylinder temperature of 220 to 240°C, and then granulated. The obtained pellet was molded into a test piece using an injection molding machine, and tested for tensile yield point strength, degree 9 flexural modulus, and Izot impact strength.

and surface cloth was measured.

In addition, the coating properties were evaluated by determining the paint residual rate (hook) by the base grain test using the following method.

In Test 1, a two-component acrylic-chlorinated polypropylene system [
F] Undercoat paint (manufactured by Cashew Co., Ltd.) with a film thickness of 10
After coating to give a film thickness of 20μ, a two-component acrylic-urethane top coat (manufactured by Cachet Co., Ltd.) was applied to the film to a thickness of 20μ, and dried at 80°C for 30 minutes. After that, it was left to stand at room temperature for 40 hours to obtain a painted product. Using a multi-cross cutter, the paint film of this painted product was cut into 100 base grooves of 1 vertical fin and 1 m horizontal, and cut at a 45 degree angle with cellophane adhesive tape. The operation of rapidly peeling off the coating film was repeated twice, and the percentage of base grains (%it) of the remaining coating film was determined.

In addition, the quality of the appearance of the large molded product was evaluated by determining whether or not 70-mer was observed in the molded product using the following method. That is, a pellet of a composition containing carbon black was supplied to a 100Z injection molding machine manufactured by Toshiba Machine ■, and the resin temperature was 250°C and the injection pressure was 1000 Ky/cf.
Ii, mold temperature 60℃, l cycle 45 seconds, complete mold for MVSS, length 367iIi+ with one end gate,
It was formed into a sheet with a width of 143 m and a thickness of 2III+, and the 70~ mark on the opposite side of the gate was judged).

In addition, pellets of the composition containing carbon black were molded using a large injection molding machine, with a length of l-1.8 m and a medium size of 5 to 3 m.
When molded into a bumper with a thickness of 0cPn and a thickness of 3 to 6H,
It had a good appearance.

Table 1 shows the melt flow index of pellets and the measurement results of molded products of polypropylene compositions containing carbon black.

Examples 2 and 3 EP R- as amorphous ethylene-propylene copolymer
In place of A, intrinsic viscosity (decalin, 135°C) 1.
7t Mooney viscosity ML1+4 (100°C) 40 amorphous ethylene-propylene copolymer (hereinafter referred to as EP'R-B)
) was used (Example 2), or the intrinsic viscosity (
Decalin, 135°C) 1.4. An amorphous ethylene-propylene copolymer (hereinafter referred to as EPR-C) with a Mooney viscosity of ML + (100°C) 10 was used (Example 3)
The rest was carried out in the same manner as in Example 1. Summary of results first
Shown in the table.

Further, a pellet of the composition containing the car pump book according to Example 2 or Example 3 was made using a large molding machine.
When molded into bumpers, all had good appearance.

Examples 4-7 Crystalline ethylene-propylene block copolymer.

The ponds were prepared by changing the blending ratios of the amorphous ethylene-propylene copolymer and talc to those shown in Table 1.

It was carried out in the same manner as in Example 1. The results are summarized in Table 1.

Further, when each pellet of the composition containing carbon black according to Examples 4 to 7 was molded into a bumper using a large molding machine, all of the pellets had a good appearance.

Example 8 Crystalline ethylene-propylene black copolymer,
Ethylene content 8.0% instead of Ep copolymer A
, boiling n-hebutane insoluble content of polypropylene component 97%
As mentioned above, the intrinsic viscosity of the soluble portion of la xylene (decalin, 135°C) at room temperature is 2.5 to 4.0.

Crystalline ethylene pyrene block copolymer (hereinafter referred to as E P :I Holima) with a melt flow index of 50
The same procedure as in Example 1 was conducted except that 60 parts of EPR-A (denoted as 0) were used and the amount of EPR-A was changed to the amount shown in Table 1. The results are summarized in Table 1.

Further, when the pellet of the composition blended with carbon black according to the example day was molded into a bumper using a large molding machine, it had a good appearance.

(Note 1) Appearance of molded product O: Shiny and no flow marks observed.

Δ: Flow marks were observed. It will be done.

×: Flow marks are noticeable.

(Note 2) Overall evaluation ○: Good, ×: Bad Comparative Example 1 As a crystalline ethylene-propylene block copolymer,
In place of BP copolymer A, the ethylene content is 9.0%, the boiling n-hebutane insoluble content of the polypropylene component is 97'% or more, and the intrinsic viscosity of the pre-warmed para-xylene soluble content (decali/,
135℃) 2.5~4.0℃ melt flow index 3! Example 1 except that 63 parts of an ethylene-propylene block copolymer (hereinafter referred to as copolymer D) was used and EPR-c was used instead of EPR-A as the amorphous ethylene-propylene copolymer. The same procedure was carried out. The results are summarized in Table 2.

Comparative example 2 As an amorphous ethylene-propylene copolymer.

Intrinsic viscosity (decalin, 135°C) 2 instead of BPR-A
．． 3. The same procedure as in Example 1 was carried out except that an amorphous ethylene-propylene copolymer (hereinafter referred to as EPR-D) having a Mooney viscosity ML of +4 (100°C) 70 was used. The results are summarized in Table 2.

Comparative example 3 Crystalline ethylene-propylene block copolymer.

The same procedure as in Example 1 was carried out except that the blending ratio of the amorphous ethylene-propylene copolymer was changed to the ratio shown in Table 2. The results are summarized in Table 2.0 The amorphous ethylene-propylene copolymers used in the Examples and Comparative Examples all had an ethylene content of 70%.

In addition, the normal temperature para-xylene soluble portion of the crystalline ethylene-propylene block copolymer used in Examples and Comparative Examples was obtained by adding Polymer 51 to para-xylene 500-
After heating the mixture to completely dissolve the polymer, it was allowed to cool and left at room temperature (approximately 23"C) day and night. The precipitated insoluble matter was removed using a centrifuge, and the remaining para-xylene solution was removed. was added to acetone 1500°C, the mixture containing the precipitated insoluble matter was filtered through a glass filter (G4), and the P fruit was dried under reduced pressure at about 50°C.

Table 2 (Note 1) Appearance of molded product ○: Shiny and no flow marks observed.

Δ: Flow marks were observed. It will be done.

×: Flow marks are noticeable.

(Note 2) Overall evaluation O: Good ×: Poor (Note 3) No flow marks were observed, but the surface was lackluster.

Patent applicant Ube Industries Co., Ltd.

Claims (1)

[Scope of Claims] Ethylene content is 5 to 10% by weight, and boiling n-hebutane insoluble content of polypropylene component is 97% by weight or more. Intrinsic viscosity of para-xylene soluble at room temperature (decalin, 135°C) 2.5-4. Melt flow index 1
1-70 crystalline ethylene-propylene block copolymer 40-75% by weight, intrinsic viscosity (decalin, 135°C)
1.0-2. O, Mooney viscosity ML1+4 (100℃)
5 to 40 amorphous ethylene-propylene copolymer 20 to 40
40% by weight of talc and 5-20% by weight of talc with an average particle size of 0.1-5 microns.